Tesla Car Charging Station

[Grouch]

Hey guys,
I attached an abbreviated version of the cutsheet for one of Tesla's car chargers.

Page 2 mentions the charger connects to a single phase, 200-240 volt power supply.

Page 3 mentions that with a 60 amp breaker, the charger can draw 48 amps at 240 volts... for a power output of 11.5 KW.

For a load such as this, what happens to the current and power output if you connect to a 208 volt panel?

For a resistive load, both power and current decrease with a voltage decrease; for a motor load, current increases and power remains the same with a voltage decrease. How do you analyze this type of load?

 

[jaggedben]

The car is going to rectify the current and regulate the internal DC charging voltage to what it wants, all carefully controlled on its end. As the battery gets closer to full its going to switch to constant voltage mode on the DC side and the current is going to ramp down, regardless of voltage from the supply. For the bulk charging at max current, it's going to take what the EVSE says it can give, unless the car itself has a lower max AC amp rating.

In other words, the voltage you supply isn't going to change the amps drawn in any meaningful way.

 

[curt swartz]

Current will stay the same but the charge rate will drop about 13%.

 

[Grouch]

In other words, the voltage you supply isn't going to change the amps drawn in any meaningful way.

But the power output will be lower then, correct? at 48 amps... 48 amps x 208 volts will be 9.98 kw, instead of 11.5 kw at 240 volts... is this correct?

 

[jaggedben]

But the power output will be lower then, correct? at 48 amps... 48 amps x 208 volts will be 9.98 kw, instead of 11.5 kw at 240 volts... is this correct?

Right.

 

[Grouch]

Thanks guys.